Reaction vessel for optical measurement

ABSTRACT

An apparatus for optical measurement is formed as a one-piece molding. The apparatus has a reaction vessel and pre-treatment vessels, at least part of the partitioning wall between the both serves as an optical waveguide body, and a light absorber vessel is formed adjacent the reaction vessel (24). Simplification of the process of manufacture thus is attained. With a light absorber accommodated in the light absorber vessel, (25), reaction components of excitation light and other noise light components that are propagated through the optical waveguide body can be sufficiently attenuated to improve the S/N ratio of the optical measurement.

FIELD OF THE INVENTION

This invention relates to apparatuses for optical measurement and, moreparticularly, to an apparatus for optically determining conditions inthe neighborhood of the surface of an optical waveguide according tomeasurement light of extremely low light intensity compared to theintensity of excitation light. One example is an apparatus forfluorescent immunity measurement, in which excitation light isintroduced into an optical waveguide to excite a label fluorescentmaterial present in the neighborhood of the optical waveguide surfacefor determining whether immunity is present or the extent thereof, ifany, according to excited fluorescent light.

PRIOR ART

A known method of optical measurement has been well known in uses a slabtype optical waveguide for exciting only label fluorescent light presentin the neighborhood of the surface of the optical waveguide with anevanescent component tidal is emitted slightly from the opticalwaveguide and determines whether immunity is present or the extentthereof, if any, according to the excited fluorescent light. FIG. 23shows an apparatus for implementing this method. The apparatus has aslab type optical waveguide 91 with all integral test solution chamber92 formed on one surface. Excitation light emitted from a laser or thelike (not shown) is led through a dichroic mirror 93 to the opticalwaveguide 91, and fluorescent light that is radiated from a labelfluorescent material is led through the optical waveguide 91 to bereflected by the dichroic mirror 93 and passed through an optical filter94 so as to be incident on a detector 95.

Where this structure is used, antibodies 96 are preliminarily attachedto kite surface of the optical waveguide 91. Antigens 97 in the testsolution are received in the antibodies 96. Further, fluorescent labelantibodies 98 that are labeled by the fluorescent body are received inthe antigens 97. The quantity of the received fluorescent labelantibodies 98 is thus determined according to the quantity of theantigens 97 present in the test solution. The evanescent component thatis obtained by introducing the excitation light into the opticalwaveguide 91 excites only label fluorescent bodies 98a of the receivedfluorescent label antibodies 98 to cause radiation of fluorescent light.Thus, the intensity of the radiated fluorescent light is proportional totime quantity of the antigens 97 in the test solution. The fluorescentlight is led through the optical waveguide 91.

Thus, the sole fluorescent light that has been guided through theoptical waveguide 91 is reflected by the dichroic mirror 93 to beincident on the detector 95 with the excitation light component blockedby the optical filter 94. In this way, it is possible to determinewhether immunity is present or the extent thereof, if any.

However, in the fluorescent immunity measurement apparatus of the aboveconstruction, it is usually necessary to dilute the antigens 97, i.e.,the liquid under test, and mix the antigens 97 and fluorescent labelantibodies 98 before accommodating the liquid under test and thefluorescent label antibodies 98. The operations of dilution and mimingare done by using a pre-treatment vessel which is preliminarilyassembled in the measurement apparatus or by using a consumablepre-treatment vessel unit which is manufactured in correspondence to thereaction vessel.

Where the pre-treatment vessel preliminarily assembled in the apparatusis used for the diluting and mixing operations, the involved mechanismis usually extremely complicated. Therefore, it is highly possible thatthe operations for the diluting and mixing are complicated. In addition,since the pre-treatment vessel is used repeatedly, residual matter thatmay remain in the pre-treatment vessel due to unsatisfactory washing maybe introduced into the liquid under test, thus leading to errors in themeasurement.

Where the consumable pre-treatment vessel unit manufactured incorrespondence to the reaction vessel is used for the dilution and themixing a considerable cost increase is inevitable because thepre-treatment vessel is formed alone. In addition, since the reactionvessel and pre-treatment vessel are a one-to-one correspondencerelation, it takes time to prepare pre-treatment vessels correspondingin number to the number of reaction vessels.

In order to preclude the above inconveniences, the inventors havethought, as shown in FIG. 24, to produce a reaction vessel 84accommodating a slab type waveguide 80. Specifically, the opposite endsof the slab type waveguide 80 are each provided with an integral lightincidence/emission prism 81. Meanwhile, a pair of pre-treatment vessels82 are formed such that they are spaced apart a predetermined distancevia a connecting section 83. The light incidence/emission prisms 81 arepressure fitted from above in the space between the opposed ends of thepaired pre-treatment vessels 82, and portions of the lightincidence/emission prisms 81 which lave no optical influence on themeasurement are engaged with the opposed ends noted above.

With the optical measurement apparatus shown in FIG. 24, however,adhesive that is coated in advance on the opposed ends noted above foebonding the light incidence/emission prisms 81 and the ends to oneanother, can get out of position when the prisms 81 are fitted. It isthus necessary to coat the adhesive again after the completion of thepressure fitting, thus leading to cumbersomeness in the operation ofmanufacturing the optical measurement apparatus. Besides, deviation ofthe angle of the light incidence/emission prisms relative to the axis oflight incidence is possible due to assembling errors. In this case, thefluorescent immunity measurement signal fluctuates, as shown in FIG. 25.Further, since the slab type optical waveguide is bare at the time ofthe assembling, it is highly possible that fingerprints and dust areattached. Further, when discharging the liquid under test from thereaction vessel 84 before accommodating fluorescent label antibodies,the liquid under test may remain in a lower space of the slab typewaveguide 80 or the like. In such a case, with the fluorescent labelantibodies poured into the reaction vessel 84, the concentration of thefluorescent label antibodies is reduced by the residual liquid undertest to result in time reduction of the accuracy of time fluorescentimmunity measurement.

Further, even by coating the adhesive again after the completion of thepressure fitting, there is no guarantee that the top surface of thepre-treatment vessels 82 and that of the light incidence/emission prisms81 are flush with one another. Therefore, when the top opening of thereaction vessel 84 is sealed after accommodating a preservation liquidtherein in order to hold the slab type optical waveguide 80 in ahumidified state during transportation and storage, the seal may becomeimperfect. Further, since the excitation light that is introduced intothe slab type optical waveguide 80 through one of the lightincidence/emission prisms 81 is emitted through the other lightincidence/emission prism 81, it is impossible to dispose a reagentvessel or the like on the extension of the slab type optical waveguide80.

DISCLOSURE OF THE INVENTION

An object of the invention is to extremely facilitate the manufacture ofoptical measurement apparatus as a whole and also dispense with thepositioning of the slab type optical waveguide and the bondingoperation.

Another object of the invention is to extremely simplify operationsnecessary for the optical measurement inclusive of the operation ofdilution and mixing.

A further object of the invention is to increase the accuracy of theoptical measurement.

To attain the above objects of the invention, there is provided anoptical measurement apparatus, which comprises a plurality of vesselsformed together as a or monolithic molding, at least one of the vesselsbeing a reaction vessel, the reaction vessel or vessels regularly facingat least one of the other vessels, time regularly facing side wall ofthe reaction vessel or vessels also serving as a slab type opticalwaveguide. Thus, the optical measurement apparatus can be obtainedsimply by injection molding or time like. In addition, since at leastone of the vessels regularly faces the reaction vessel or vessels andthe regularly facing side wall of the reaction vessel or vessels alsoserves as a slab type optical waveguide, it is possible to prevent theinconveniences which result when an operator's fingers or the like touchthe slab type optical waveguide.

Further, the slab type optical waveguide is disposed substantiallyvertically and, with settling and deposition of disturbing mattercontaining in the liquid under test, most of the reaction surface of theslab type optical waveguide can be held free from the influence of thedeposited disturbing matter. Thus, it is possible to permit satisfactoryoptical measurement.

The slab type optical waveguide may be one with antigens, antibodies orhaptens that are preliminarily attached to at least one side surface. Inthis case, it is possible to permit optical determination of whetherimmunity is present and the extent thereof, if any.

Suitably, the slab type optical waveguide is disposed in an inclinedstate such that the reaction vessel has a narrowed bottom. In this case,it is possible to readily separate molding dies after injection moldingor the like. In addition, it is possible to improve the smoothness ofthe slab type waveguide surface.

Further, suitably some of the vessels other than the reaction vessel orvessels are pre-treatment vessels. In this case, when carrying outoptical measurement with the optical measurement apparatus obtained byinjection molding or the like, the liquid unter test, diluting solution,etc. may be accommodated in some of the plurality of pre-treatmentvessels. By so doing, it is possible to permit the operation of dilutingthe liquid under test to be easily attained by using a desiredpre-treatment vessel and also permit the optical measurement to beeasily attained by pouring the solution after completion of necessarypre-treatment into a reaction vessel.

In this case, a plurality of pre-treatment vessels may be provided suchthat they include a reagent vessel and/or a diluting solution vessel,whereby the same functions as above are attainable.

In the above cases, suitably one of the pre-treatment vessels is areagent vessel, which stores a fluorescent material and is disposed suchas to regularly face none of the reaction vessel side walls. In thiscase, when the fluorescent material in the reagent vessel is excited byexcitation light propagated while being totally reflected in proceedingthrough the slab type optical waveguide, the effects of fluorescentlight emitted from the fluorescent material on the reaction vessel canbe extremely reduced to eventually increase the sensitivity of theoptical measurement.

Suitably, the optical measurement apparatus has a seal applied to coverat least the reagent and dilution solution vessels. This arrangementpermits the reagent and dilution solution in time respective vessels tobe held reliably in the vessels even when the optical measurementapparatus is vibrated during storage, transport, etc. Of course a seriesof operation necessary for optical measurement may be performed byseparating the seal.

Further, the slab type optical waveguide has a light incidence/emissionprism provided at one end for introducing excitement light into it inorder for the excitement light to be propagated while being totallyreflected and also for emitting signal light containing opticalmeasurement information, and suitably a light absorber vessel isdisposed such that it corresponds to the other end of the slab typeoptical waveguide. In this case, the light absorber contained in timelight absorber vessel can absorb fluorescent light or the like, which isgenerated by the slab type optical waveguide as noise component withrespect to time measurement light, with propagation of the excitementlight introduced into the waveguide through the excitement lightintroduction prism. It is thus possible to extremely reduce fluorescentlight or time like returning toward time excitement light introductionprism. Of course, the light absorber contained in the light absorbervessel can absorb the introduced excitement light, thus extremelyreducing excitement light which is reflected by other portions than Theslab type optical waveguide to be introduced into the reaction vessel.It is thus possible to permit measurement light substantially free froma noise component to be emitted from the excitement light introductionprism, thus extremely increasing the accuracy of the opticalmeasurement. Further, the optical absorber need not be coated on theslab type optical waveguide but may be merely accommodated in the lightabsorber vessel. That is, no particular consideration is needed for anyrange of coating of the light absorber. In addition, since the lightabsorber is not touched by the liquid under test, it is possible toextremely broaden the scope of applications of the light absorber.

Further, time slab type optical waveguide has a light incidence/emissionprism provided at one end for introducing excitement light into it inorder for the excitement light to be propagated while being totallyreflected and also for emitting signal light containing opticalmeasurement information, and suitably it also has a total reflectionprism provided at the other end for emitting the excitement light in adirection at a predetermined angle with respect to its optical axis. Inthis case, when the excitement light that has been introduced into theslab type optical waveguide through the excitement light introductionprism is emitted, it is totally reflected by the total reflection prism,and thus it is possible to let the direction of extension of the slabtype optical waveguide and time direction of the excitement lightemission be sufficiently different. The reagent vessel of the like thuscan be disposed on the extension of the slab type optical waveguide, andit is possible to increase the degree in freedom of vessel disposition.Further, it is possible to readily cope with an increase of the numberof vessels. Further, when the slab type optical waveguide itself emitsfluorescent light or the like which is a noise component with respect tothe measurement light, that which is returning toward the excitementlight introduction prism can be extremely reduced, thus eventuallyincreasing the accuracy of the optical measurement.

Further, the slab type optical waveguide has a light incidence/emissionprism provided at one end for introducing excitement light into it inorder for the excitement light to be propagated while being totallyreflected, and suitably light blocking means for blocking light isprovided in a predetermined area adjacent an excitement lightintroduction area of the light incidence/emission prism. In this case,it is possible to reliably prevent excitement light from beingintroduced through the area adjacent the excitement light introductionarea of the excitement light introduction prism. In addition, it ispossible to reliably prevent emission of scattered light, generatedlight, etc., in other areas than the slab type optical waveguide and thesurface neighborhood. Thus, the proportion of noise light componentcontained in the measurement light can be extremely reduced to extremelyincrease the accuracy of the optical measurement.

Further, of the side walls of the reaction vessel, that which extendssubstantially perpendicular to and located on the excitement lightintroduction side of the slab type optical waveguide and/or that whichextends substantially parallel to the slab type optical waveguide,are/is suitably coated with a black paint. In this case, when excitementlight intrudes into the reaction vessel as it is introduced into theslab type optical waveguide, the coated black paint can absorb the noisecomponent due to the intruding excitement light, thus reducing theradiation of the noise component to the outside of the reaction vessel(i.e., to the outside on the excitement light introduction side).Further, when excitement light intrudes into the reaction vessel as itis led by scattering or the like to side walls facing the slab typeoptical waveguide after having been propagated through the waveguide,the coated black paint can absorb the intruding excitement light. It isthus possible to reduce the excitement light component intruding intothe reaction vessel and hence reduce the noise component due to thisexcitement light.

Further, suitably the optical measurement apparatus further comprises alight detector for detecting signal light emitted from the slab typeoptical waveguide and also an analyzer for analyzing immunity reactionsaccording to detection signals from the light detector. In this case,with excitement light introduced in the slab type optical waveguide forpropagation through the same while being totally reflected, signal lightindicative of the optical character of the neighborhood of the slab typeoptical waveguide surface is emitted from the waveguide. This signallight can be detected by the light detector for immunity reactionanalysis in the analyzer according to detection signals from the lightdetector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a fluorescent immunity measurementapparatus as an embodiment of the optical measurement apparatusaccording to the invention;

FIG. 2 is a sectional view taken along line II--II in FIG. 1;

FIG. 3 is a sectional view taken along line III--III in FIG. 1:

FIG. 4 is a sectional view showing a vessel form;

FIG. 5 is a view showing a sectional profile of the vessel;

FIG. 6 is a sectional view for schematically explaining optical immunitymeasurement;

FIG. 7 is a view for explaining an inconvenience of an opticalmeasurement apparatus without light absorber vessel;

FIG. 8 is a view showing optical immunity measurement results:

FIG. 9 is a schematic perspective view showing a different embodiment ofthe optical immunity measurement apparatus according to the invention;

FIG. 10 is a fragmentary sectional view;

FIG. 11 is a schematic view showing a measurement apparatus for carryingout optical measurement with the optical measurement apparatus shown inFIG. 9;

FIG. 12 is a graph showing a fluorescent light signal obtained with theembodiment of the optical measurement apparatus shown in FIG. 9 and afluorescent light signal obtained with an optical measurement apparatuswithout any light blocking member, these signals being plotted againsttime;

FIG. 13 is a graph showing a calibration curve obtained with theembodiment of the optical measurement apparatus shown in FIG. 9 and thatobtained with an optical measurement apparatus without light blockingmember;

FIG. 14 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention;

FIG. 15 is a fragmentary enlarged-scale view showing the sameembodiment;

FIG. 16 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention;

FIG. 17 is a sectional view showing a still further embodiment of theoptical measurement apparatus according to the invention;

FIG. 18 is a sectional view showing yet further embodiment of theoptical measurement apparatus according to the invention;

FIG. 19 is a perspective view showing a further embodiment of theoptical measurement apparatus according to the invention;

FIG. 20 is a sectional view taken along line XX--XX in FIG. 19;

FIG. 21 is a bottom showing the optical measurement apparatus shown inFIG. 19;

FIG. 22 is a schematic view showing a reaction mechanism using a biotinlabel antibodies and fluorescent label avidin;

FIG. 23 is a schematic view showing a prior art optical measurementapparatus;

FIG. 24 is an exploded perspective view showing a prior art proposedimprovement over optical measurement apparatus; and

FIG. 25 is a graph showing fluctuating fluorescent immunity measurementsignal obtained with the optical measurement apparatus shown in FIG. 24.

BEST FORMS OF CARRYING OUT THE INVENTION

FIG. 1 is a perspective view showing a fluorescent immunity measurementapparatus as an embodiment of the optical measurement apparatusaccording to the invention. FIGS. 2 and 3 are sectional views takenalong lines II--II and III--III in FIG. 1, respectively. In FIG. 1, theinternal structure is not shown. This fluorescent immunity measurementapparatus has two pre-treatment vessels 21 and 22, which are provided inpredetermined portions of a casing 2 in a side-by-side arrangement inthe longitudinal direction of the casing, and a reaction vessel 24regularly facing the entire pre-treatment vessel 21 and substantiallyone half of the pre-treatment vessel 22. A light absorber vessel 25 isprovided such that it regularly faces the rest of the pre-treatmentvessel 22 and is located on an extension of the reaction vessel 24. Afurther pre-treatment vessel 23 is provided such that it regularly facesthe pre-treatment vessel 22 and light absorber vessel 25. Timepre-treatment vessels 21 and 22, reaction vessel 24 and light absorbervessel 25, are defined by a partitioning member 26. The partitioningmember 26 has an upper half portion 26a having a predeterminedthickness. Its lower half portion includes a partitioning wall 26bexclusive for the pre-treatment vessels 21 and 22 and a partitioningwall 11 exclusive for the reaction vessel 24 and the light absorbervessel 25. The partitioning wall 11 has highly accurately flat oppositesurfaces and also serves as an optical waveguide body 11 of the slabtype optical waveguide 1. A narrow space is defined between thepartitioning walls 26b and 11, and it can prevent such inconvenience asattachment of fingerprints or dust to the optical waveguide 11 caused bybeing touched by fingers or hands. An excitation light introductionprism 12 is provided such that it faces the reaction vessel side end ofthe optical waveguide body 11. The casing 2, which has the pre-treatmentvessels, reaction vessel, light absorber vessel, optical waveguide body,excitation light introduction prism, etc., is formed as a one-piecemolding by injection molding or the like. The light absorber vessel 25is filled with a light absorber 25a, which is composed of a black paint,a silicone resin, etc. The light absorber may not be black in case wherethe excitation light is not white light. The slab type optical waveguide11 is not exactly vertical but is slightly inclined from the vertical sothat the reaction vessel 24 is narrow at the bottom and broad in anupper portion. This arrangement permits surface polishing to be attainedhighly accurately and also permits polishing dust to be easily removed.Further, it permits die separation to be easy at the time of themolding. Further, since the reaction vessel 24 formed in the above wayis progressively broader as one goes up from the bottom and also freefrom any stepped portion, it is possible to remove liquid under testthat has been distributed into the vessel substantially perfectly beforedistribution of a solution containing fluorescent label antibodies: Itis thus possible to reliably preclude the inconvenience of reaction ofthe fluorescent label antibody concentration. Further, at least aportion of the side wall of the reaction vessel 24 is made transparent.The movement of a pipette or the like thus can be confirmed with thetransparent portion of the vessel when distributing the liquid undertest or the like.

After the fluorescent immunity measurement apparatus having the aboveconstruction has been obtained, a solution is accommodated in apertinent pre-treatment vessel, a preservation liquid for preservingantibodies 3 is accommodated in the reaction vessel 24, and the topopenings 21a to 24a of the pre-treatment and reaction vessels 21 to 24are covered by mounting a seal member 6. Thus, leakage of liquid duringtransport, storage, etc. can be reliably prevented. In this case, theseal member 6 is attached to the optical measurement apparatus which isin the form of a one-piece molding, it is possible to reliably preventsuch inconvenience that the seal becomes imperfect.

However, if burrs are generated on the seal surface provided by the sealmember 6, they give rise to such inconvenience that liquid having beenraised by capillary phenomenon along the interface between the sealmember 6 and vessel and present on the seal surface may cause defectivefusion between the seal member 6 and seal surface, thus resulting inleakage or evaporation of liquid. FIG. 4 is a schematic sectional viewshowing a vessel formation arrangement, which can prevent generation ofthe former inconvenience. In this case, the vessel is formed by using adie 61 for forming the vessel body and a die 62 for forming a groovealong the edge of the opening of the vessel body. The width and heightof the groove are both sufficiently about 0.2 mm. In this case, burrsare produced between the die 61 for the formation of the vessel body andthe adjacent die 62. However, by setting the depth of the groove to begreater than the height of the burrs, it is possible to preventdefective seal due to the burrs. Further, since a plurality of dies 61and 62 are used, a corner R is produced at a portion which is to be acorner edge. It is thus possible to eliminate the inconvenience offormation of line contact between the seal member 6 and seal surface.

FIG. 5 shows the sectional profile of vessel which can prevent thegeneration of the latter inconvenience. This vessel has a shoulder 63formed at a predetermined position. Thus, its upper portion 64 has anincreased width. In addition, an auxiliary wall 66 is formed along themost inner edges of the shoulder such that it extends along theextension of the side walls of a lower portion 65 of the vessel. Thewidth of the shoulder 63 and the height of the auxiliary wall 66 areboth sufficiently about 0.5 mm. Thus, when the lower portion 65 of thevessel is filled with liquid 67 such that the liquid is in a swellingstate due to the surface tension, there is no possibility that theliquid 67 unnecessarily approaches the section of contact between theseal member 6 and seal surface 68. Also, there is no possibility thatthe liquid 67 rises due to the capillary phenomenon. Thus, a reliableseal can be attained with the seal member 6.

For carrying out immunity measurement by using the fluorescent immunitymeasurement apparatus, which is formed in the above way and accommodatessolution, first the seal member 6 is separated, then the solutioncontaining antigens 31 is diluted n the pre-treatment vessel 23 bytaking out the diluting solution from the pre-treatment vessel 21, andthen a reagent containing fluorescent label antibodies 32 is diluted inthe pre-treatment vessel 22. The reagent may be diluted simultaneouslywith or after the dilution of the liquid under test. Then, the dilutedliquid under test is poured into the reaction vessel 24. Then, theantigens 31 are caused to be received in the antibodies 3 that areattached to the optical waveguide 11, and then the liquid under test inthe reaction vessel 24 is discharged. Then, as shown in FIG. 6,excitation light that is emitted from an excitation light source 4a isled via an optical system 4b and dichroic mirror 4 to the prism 12, andthen the reagent which has been diluted in the pre-treatment vessel 21is poured into the reaction vessel 24 in the casing 2. In this way,fluorescent light corresponding to the quantity of the antigens 31 canbe obtained.

More specifically, with the reagent poured into the reaction vessel 24,the fluorescent label antibodies 32 in the reagent are received in theantigens 31 received in the antibodies 3. Thus, fluorescent labelantibodies 32 corresponding in quantity to the quantity of the antigensin the liquid under test, are restrained in the neighborhood of thesurface of the optical waveguide 11.

The excitation light as measurement light is diffracted by the prism 12to be introduced into the optical waveguide body 11 for propagationtherethrough while being totally reflected. Thus, only the labelfluorescent bodies 32a of the restrained fluorescent label antibodies 32noted above are excited by the evanescent component of the excitationlight to radiate peculiar fluorescent light.

This fluorescent light is partly propagated through the opticalwaveguide body 11 to be emitted from the prism 12 for reflection by thedichroic mirror 4 and optical system 4c including a filter to be led tothe detector 5. In the prior art optical measurement apparatus,fluorescent light excited in the optical waveguide body 11, Ramanscattering, etc. are reflected by the end surface of the opticalwaveguide body to be emitted from the light incidence side. In thisembodiment, both the excitation light and fluorescent light that havebeen propagated up to a position corresponding to the light absorbervessel 25, are both absorbed by the light absorber 25a accommodated inthe light absorber vessel 25. It is thus possible to reliably eliminatereflection from the light emission end of the optical waveguide body 11.In this connection, if the optical measurement apparatus without theoptical absorber vessel 25 is adopted, the excitation light, forinstance, is reflected to some extent at the light emission end of theoptical waveguide body 11, as shown in FIG. 7. The reflected light isintroduced into the reaction vessel 24 to excite the label fluorescentbodies of the floating fluorescent label antibodies, and fluorescentlight emitted from the label fluorescent bodies functions as noisecomponent. In this embodiment, however, the reflected component of theexcitation light from the light emission end can be removed, as notedbefore, and thus the noise component can be reduced. Designated at 4d isa light-receiving element for monitoring the intensity of the excitationlight.

Thus, the reflected component of excitation light and also thefluorescent light excited in the optical wave guide body 11, Ramanscattering, etc., these being incident on the detector 5, can beextremely reduced to increase the accuracy of measurement. Further,there is a reflection component when the excitation light is incident onthe prism 12. This reflection component, however, is propagated in adirection which is irrelevant to the measurement and does not functionas background noise. FIG. 8 is a view showing the immunity strengthcorresponding to the amount of β-2 microgrobulin. It will be seen thatthe background noise can be greatly reduced by using the light absorbercharged in the light absorber vessel 25. In FIG. 8, white squaresrepresent the case of using light absorber, and black squares representthe case of using no light absorber. As is obvious from FIG. 8, withoutuse of any light absorber the sensitivity of measurement is 1×10⁻¹¹ M,whereas by using the light absorber it is increased up to 6×10⁻¹² M.Further, in the case of setting the wavelength of the excitation lightto 495 nm and using FITC as the fluorescent pigment, the S/N ratio(i.e., the ratio between the real immunity signal value and an off-setstray light signal value) is 0.136, which is 1.94 times the value in thecase of using no light absorber.

Further, the optical waveguide body 11 is formed to be substantiallyvertical. Thus, when proteins and like disturbance matter in the liquidunder test settle and deposited, the surface, to which antibodies areattached, is hardly covered by the deposited matter. It is thus possibleto introduce measurement light of a sufficient intensity into theoptical waveguide body 11. Further, since the fluorescent light immunitymeasurement apparatus is formed as a one-piece molding, there issubstantially no fluctuation of the position, at which the prism 12 isformed. Thus, fine adjustment of the prism position for the fluorescentlight immunity measurement is unnecessary.

Further, since the liquid under test can be discharged substantiallycompletely before distributing the reagent containing fluorescent labelantibodies, it is possible to obtain measurement results with very lessfluctuations compared to the case of fluorescent light immunitymeasurement using the apparatus shown in FIG. 24, as shown in Table 1below. In the table, n represents the number of times of repetition, β2m represents β2 microgloburin, and CRP represents C-reactive protein.

                  TABLE 1                                                         ______________________________________                                                               Optical measure-                                                 Optical measure-                                                                           ment apparatus in                                                ment apparatus in                                                                          according to the                                                 FIG. 24      invention                                              ______________________________________                                        Residual     52.1 μl     20.9 μl                                        value                                                                         (n = 5)                                                                       CV vlaue     44.9%          10.5%                                             Fluorescent 114.0          147.5                                              light immu-                                                                   nity measure-                                                                 ment signal                                                                   (n = 6)                                                                       CV value     12%            1.6%                                                          (high concentra-                                                                             (high concentra-                                               tion β 2 m)                                                                             tion CRP)                                          ______________________________________                                    

Further, since at least part of the side walls of the reaction vessel 24is transparent, the position of distribution of the liquid under test orthe like could be confirmed with the eyes, and thus fluctuations of thefluorescent light immunity measurement due to fluctuations of thedistribution position could be greatly suppressed. Table 2 below showsfluorescent light immunity measurement signals and fluctuations thereofwhen the position of the distribution of the liquid under test was setto a left and a right position, indicating that the extent of stirringvaries depending on the position of the distribution.

                  TABLE 2                                                         ______________________________________                                                         Position of distribution                                                      of liquid under test                                                          Left  Right                                                  ______________________________________                                        Fluorescent light immu-                                                                          103.1   117.6                                              nity measurement signal                                                       (n = 6)                                                                       CV value           4.0%    2.9%                                               ______________________________________                                    

In this embodiment, a nozzle for the operations of diluting the liquidunder test and reagent and pouring the diluted solution and reagent intothe reaction vessel 24, is moved along an orbit as shown by arrow A inFIG. 1. As is seen, the orbit is an arcuate simple one, and thus thecontrol of the nozzle for the above operations can be simplified.Further, it is possible to off-set the reaction vessel 24 to reduce thethermal resistance so as to reduce the taken for the reaction solutionto be elevated in temperature from the preservation temperature (forinstance 4° C.) to the reaction temperature (for instance 37° C.).However, it is possible to use the sole pre-treatment vessel 23 fordiluting the liquid under test containing the antigens 31 and pouringthe fluorescent label antibodies 32 for mixing. In this case, there isno need of using the pre-treatment vessel 22.

In this embodiment, the inner surfaces of the light absorber vessel 25is suitably polished to be like a mirror surface. By so doing, it ispossible to greatly suppress random reflection of the excitation lightdue to otherwise present irregularities of the inner surfaces of thelight absorber vessel 25. Thus, the efficiency of absorption of theexcitation light by the light absorber 25a can be increased to obtainsatisfactory reproducibility in a low concentration range. As a specificexample, the coarseness of two molding samples (which are shaped at atime, for instance) was measured in a state, in which the inner surfacesof the light absorber vessel 25 had been polished by #2,000 polishing,and also in a state, in which the inner surfaces were had been furtherpolished by #20,000 polishing. Further, the reproducibility wasevaluated by measuring the CV values in the high and low concentrationranges.

Table 3 shows the coarseness of the moldings, and Table 4 shows theresults of the reproducibility evaluation. In the tables, Ra representsthe projection (μm) from an average line, Rz (DIN) represents the meancoarseness (μm) for 10 points, and the reproducibility evaluation valuerepresents the fluctuations (CV values) from the average value. "Beforepolishing" means the state after the sole #2,000 polishing, and "Afterpolishing" means the state after the #20,000 polishing.

                  TABLE 3                                                         ______________________________________                                                 Sample 1         Sample 2                                                     Before                                                                              After      Before  After                                                poli- Poli-      Poli-   Poli-                                                shing shing      shing   shing                                       ______________________________________                                        Ra         0.16    0.08       0.18  0.08                                      Rz (DIN)   1.16    0.48       1.22  0.58                                      ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                                  Sample 1        Sample 2                                                      Before                                                                              After     Before  After                                                 Poli- Poli-     Poli-   Poli-                                                 shing shing     shing   shing                                       ______________________________________                                        High concent-                                                                              4%     10%        7%   7%                                        ration range                                                                  Low concent-                                                                              10%      5%       25%   7%                                        ration range                                                                  ______________________________________                                    

As is clear from the these measurement results, by providing thepolishing the surface roughness of the inner surfaces of the lightabsorber vessel 25 is extremely improved (i.e., the surfaces are madeextremely flat), thus extremely improving the reproducibility ofmeasurement in the low concentration range. In the high concentrationrange, however, the reproducibility of measurement is not changed orrather reduced. This is thought to be due to the fact that influence ofthe apparatus is liable in the low concentration range while influenceof the fluctuations of the immunity reaction itself is liable in thehigh concentration range.

Embodiment 2

FIG. 9 is a schematic perspective view showing a different embodiment ofthe optical measurement apparatus according to the invention. FIG. 10 isa fragmentary sectional view. This embodiment is different from thepreceding optical measurement apparatus shown in FIG. 1 only in thatlight blocking members 27 are provided in predetermined areas except forand adjacent to an excitation light introduction area (i.e., measurementlight emission area) on the side of the prism 12. Again in FIG. 9, theinternal structure of the apparatus is not shown.

The light blocking member 27 may use both light absorber and lightreflector. The light blocking member 27 made of a light absorber may becoated with a black paint. Instead, it is possible to form an integralblack synthetic resin layer on one side of a transparent syntheticresin. The light blocking member 27 made of a light reflector may beformed by applying a metal foil or the like.

FIG. 11 schematically shows the overall structure of a measurementsystem for making optical measurement with the optical measurementapparatus shown in FIG. 9. Light emitted from a He--Ne laser 41 as anexcitation light source is led via a ND (neutral density) filter 42, alight chopper 43 and a lens system 44 including a dichromic mirror 44ato the excitation light introduction area of the prism 12, andmeasurement light emitted from the excitation light introduction area ofthe prism 12 is led by the dichroic mirror 44 in the lens system 44 in adirection different from the excitation light and then led via a sharpcut filter 45 to a photoelectron multiplier 46, The photoelectronmultiplier 46 provides an output current, which is amplified by an I/Vconverter 47, then detected by a lock-in amplifier 48 and then amplifiedby an A/D converter 49 before being fed to a computer 50 for variouskinds of signal processing. To the lock-in amplifier 48 is supplied asynchronous signal corresponding to the operation of the light chopper43.

The optical measurement apparatus having the above structure operates asfollows.

Light from the He--Ne laser 41 is modulated in the light chopper 43 andthen led to the optical measurement apparatus. In the opticalmeasurement apparatus, the excitation light is introduced from the soleexcitation light introduction area of the prism 12. As the introducedexcitation light is propagated through the optical waveguide body 11,its evanescent wave component excites the fluorescent label antibodies32 which are restrained in the neighborhood of the surface of theoptical waveguide body 11, thus generating fluorescent light having apredetermined wavelength.

The fluorescent light generated from the fluorescent label antibodies32, is propagated through the optical waveguide body 11 to be emitted asmeasurement light from the sole excitation light introduction area ofthe prism 12 and led to the photoelectron multiplier 46. At this the,light due to light generation, scattering, etc. in other portions thanthe neighborhood of the surface of the optical waveguide body 11, isblocked by the light blocking member 27. Thus, it is reliably preventedfrom being led as noise light component with respect to the measurementlight to the photoelectron multiplier 46.

Thus, it is possible to extremely increase the S/N ratio of the outputcurrent (i.e., measurement signal) from the photoelectron multiplier 46and hence extremely increase the sensitivity of the,optical measurementusing the optical measurement apparatus.

FIG. 12 shows a fluorescent signal obtained with the embodiment of theoptical measurement apparatus (refer to A in FIG. 12) and a fluorescentsignal obtained with an optical measurement apparatus without the lightblocking member 27 (refer to B in FIG. 12), these fluorescent signalsbeing plotted against time. It will be seen that with this embodimentthe noise level can be greatly reduced.

In this specific example, as the light blocking member 27 is used one,which is obtained by coating a black paint for acrylic acid resin, andthe illustrated fluorescent signals are obtained in the measurement of 1ng/ml of β-2 microglobulin. In FIG. 12, labelled A1 and B1 are noiselevels, and labelled A2 and B2 are measurement signal levels based onβ-2 microglobulin. Of these fluorescent signals, the S/N ratio at apoint of substantial saturation of the measurement signal is 1.3 and0.6, respectively. Thus, it will be seen that in this embodiment the S/Nratio is extremely improved.

FIG. 13 is a view showing a calibration curve (see white circles in FIG.13) obtained by using the embodiment of the optical measurementapparatus and that (see black circles in FIG. 13) obtained by using anoptical measurement apparatus without the light blocking member 27. Inthe latter the sensitivity of measurement is 1×10⁻¹¹ M, while it is1×10⁻¹² M in the latter. It will be seen that the sensitivity ofmeasurement can be extremely increased.

While in this embodiment the light absorber 25a is not used, it ispossible to use the light absorber 25a. In this case, it is possible toimprove the S/N ratio and the sensitivity of measurement morepronouncedly.

Embodiment 3

FIG. 14 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention. This embodiment isdifferent from the embodiment shown in FIG. 1 in float the lightabsorber vessel 25 is omitted and that the trailing end of the opticalwaveguide body 11 is formed with an integral total reflection prism 16such that excitation light having been propagated through the opticalwaveguide body 11 is emitted in a direction at a predetermined angle(for instance 90°) to the optical axis of the optical wave, guide body11.

The total reflection prism 16 has an area, which constitutes anextension of one surface of the optical waveguide body 11 and has alength L, an area, which constitutes a surface extending substantiallyperpendicularly from a surface opposed to the afore-mentioned onesurface of the optical waveguide body 11, and a total reflection area16a (and is at an angle of 35°, for instance, with respect to the abovelength L area), which is continuous to the above area with the length L(see FIG. 15). Denoting the thickness of the optical waveguide body 11by d and the excitation light propagation angle by θ, the length L notedabove may be set to satisfy

    L≧d/tan θ

If this is done so, the excitation light propagating through the opticalwaveguide body 11 can be wholly totally reflected by the totalreflection surface 16a to be emitted in the direction noted above.

Thus, it is possible to dispose the pre-treatment vessel 23, such as areagent vessel, at a position oil the extension of the optical waveguidebody 11 to reliably preclude the influence of the excitation light onthe pre-treatment vessel 23 disposed in this way. It is thus possible toincrease the degree of freedom of the pre-treatment vessel dispositionand also easily increase the number of pre-treatment vessels or the likethat are to be disposed. Further, in the case of this embodiment, costreduction compared to the embodiment shown in FIG. 1 is attainablebecause the light absorber 25a is unnecessary.

Embodiment 4

FIG. 16 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention. This embodiment isdifferent from the embodiment shown in FIG. 1 in that the light absorbervessel 25 is omitted and that substantially the entire outer surface ofthe wall of the reaction vessel 24 that opposes the optical waveguidebody 11 is coated with black paint 24b. The black paint 24b that may beused is any paint having no influence on the solution to be poured intothe reaction vessel 24. In the figure, no shading is used in order toclearly show the path of propagation of the excitation light. The dashedline shows an example of scattered component of the excitation light inthe case where the black paint 24b is not coated.

The excitation light laving been propagated through the opticalwaveguide body 11 is scattered or reflected, so that it is partly led tothe side wall opposing the optical waveguide body 11. However, theexcitation light that has been led to the side wall with black paint isabsorbed by the black paint 24b and sufficiently attenuated. Thus, it ispossible to extremely reduce the intensity of light that is led from theside wall noted above into the reaction vessel 24. Consequently, it ispossible to extremely reduce the noise component due to excitation lighton the basis of the above path. As a specific example, with theexcitation light wavelength set to 495 nm while using FITC as the labelfluorescent material, the S/N ratio (i.e., the ratio of the realimmunity signal value to the stray light signal value as an off-set) was0.146, which is 2.09 times the value in the case where the black paintis not used. Suitably, instead of coating the outer surface of the sidewall with the black paint 24b, the inner surface of the side wall iscoated with black paint.

Of course, it is suitable to use the light absorber vessel 25 as well,as shown by phantom line in FIG. 16. In this case, it is possible tofurther increase the noise component reduction effect.

Embodiment 5

FIG. 17 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention. This embodiment isdifferent from the embodiment shown in FIG. 16 only in that, instead ofcoating the black paint 24b on substantially the entire surface of theside wall of the reaction vessel 24 opposing the optical waveguide body11, the inner surface of the wall, which extends perpendicularly to theoptical waveguide body 11 and is located on the side of the prism 12, iscoated with black paint 24c. In the figure, no shading is used in orderto clearly show the path of propagation of the excitation light.

Thus, like Embodiment 2 of the optical measurement apparatus, it ispossible to reduce the noise level. In Embodiment 2 of the opticalmeasurement apparatus, the noise component that is radiated from thereaction vessel 24 and led to the prism 12, can not be blocked. Incontrast, in this embodiment the noise component radiated from thereaction vessel 24 can be reliably prevented from being led to the prism12. It is thus possible to attain higher noise level reduction effects.As a specific example, with the excitation light wavelength set to 495nm while using FITC as the label fluorescent material, the S/N ratio(i.e., the ratio of the real immunity signal value to the stray lightsignal value as an off-set), was 0.273, which is 3.90 times the value inthe case of using no black paint.

This embodiment will further be described.

The excitation light having been led through the prism 12 into theoptical waveguide body 11, is propagated through the same while beingtotally reflected. However, since the surfaces of the optical waveguidebody 11 are not perfectly flat surfaces, the excitation light partlyintrudes into the reaction vessel 24. In addition, the angle ofincidence of the excitation light fluctuates to a certain extent, andtherefore the excitation light partly intrudes into the reaction vessel24 due to its first reflection by the prism 12. Such intruding lightexcites the label fluorescent material floating in the reaction vessel24, thus causing generation of fluorescent light from the floating labelfluorescent material. In this embodiment, the black paint 24c preventsthe fluorescent light generated by the floating label fluorescentmaterial from being emitted toward the prism 12. It is thus possible toattain higher noise level reduction effects as noted above.

Embodiment 6

FIG. 18 is a sectional view showing a further embodiment of the opticalmeasurement apparatus according to the invention. This embodiment isdifferent from the embodiment shown in FIG. 16 only in that the innersurface of the side wall of the reaction vessel 24 that extendsperpendicularly to the optical waveguide body 11 and is located on theside of the prism 12 is also coated with the black paint 24c. In thefigure, no shading is used to clearly show the path of propagation ofthe excitation light.

Thus, in this embodiment the effects obtainable in Embodiments 4 and 5can be attained in combination to attain yet higher noise levelreduction effects.

Embodiment 7

FIG. 19 is a perspective view showing a further embodiment of theoptical measurement apparatus according to the invention. FIG. 20 is asectional view taken along line XX--XX in FIG. 19, and FIG. 21 is abottom view of the embodiment. The optical measurement apparatus is madeof material laving transparency in its entirety. This opticalmeasurement apparatus is different from the embodiment shown in FIG. 1in that, in lieu of the pre-treatment vessels 21 and 22, a dilutingsolution vessel 51, a stirring vessel 52, a multi-function vessel 53 anda label solution vessel 54 are disposed in the mentioned order such thatthe diluting solution, stirring and multi-function vessels 51 to 53regularly face the reaction vessel 24 and that the label solution vessel54 regularly faces the light absorber vessel 25 and also that adetection vessel 55 is provided in lieu of the pre-treatment vessel 23.

The embodiment will further be described.

The diluting solution vessel 51 is for accommodating a solution(diluting solution) for diluting the liquid under test. The stirringvessel 52 is for attaining the stirring of the liquid under test and thediluting solution both poured into it. To this end, a nozzle (not shown)is used to carry out the withdrawal and discharge of the blend solutionrepeatedly a necessary number of times. The multi-function vessel 53 isused for accommodating a reagent for increasing dilution factor orincreasing the sensitivity of the optical measurement. Morespecifically, for increasing the dilution factor, using a nozzle (notshown) the diluted liquid under test in the stirring vessel 52 and thediluting solution are poured, and the blend solution is withdrawn anddischarged repeatedly for a necessary number of times. For the latterpurpose, a solution containing biotin label antibodies 73 labelled bybiotin 73a is poured in advance. The label solution vessel 54 is foraccommodating a solution containing fluorescent label antibodies 32labelled by label fluorescent material 32a or fluorescent label avidin72 labelled by label fluorescent material 72a. This vessel regularlyfaces none of the side walls of the reaction vessel 24. Thus, when thelabel fluorescent material is excited by excitation light propagatedthrough the optical waveguide body 11 and thus generates fluorescentlight, the generated fluorescent light hardly has influence on thereaction vessel 24. The detection vessel 55 is for temporarilyaccommodating the liquid under test, such as blood. Although notparticularly shown, a seal member made of aluminum or the like isprovided to cover all the vessels except the detection vessel 55. Thedetection vessel 55 has its side wall top formed with a notch 55a,through which the liquid under test is to be introduced. In addition, ithas a narrowed lower portion such that it substantially regularly facesonly the label solution vessel 54. A vertically extending engagementrecess 56a is formed such that it corresponds to the notch 55a. Anotherengagement recess 56b is formed at a predetermined position adjacent theprism 12. The positioning of the prism 12 with respect to the opticalaxis of the optical system, can be attained by engaging together the twoengagement recesses 56a and 56b with chuck pawls (not shown), forinstance.

Of the diluting solution, stirring, multi-function and label solutionvessels 51 to 54 the side wall 57 on the side of the reaction vessel 24is inclined and has a shoulder 57a at an intermediate height position.Of the inclined side wall 57, the portion 57b on the lower side of theshoulder 57a regularly faces the optical waveguide body 11 with a slightgap provided relative thereto. The portion 57c of the wall 57 on theupper side of the shoulder 57a also serves as the side wall of thereaction vessel 24. The side wall 57d which opposes the inclined sidewall 57 has an opposite inclination. Of course the side wall 57e of thereaction vessel 24 which opposes the side wall 57c has an oppositeinclination to that of the optical waveguide body 11. The shoulder 57aand all the inclined side walls 57b to 57c, are equal in thickness tothe bottom, thus permitting great reduction of deformation at the timeof the molding. The inclination of each of the inclined walls 57b to 57eis set to about 3° with respect to the vertical plane, thus facilitatingthe die separation at the time of the molding. The optical waveguidebody 11 has an inclination angle of about 9° to the vertical plane, andits surfaces formed by molding are formed to be like a mirror surface.Further, auxiliary walls 58a to 58f extending horizontally from thesurface with the prism 12 formed thereon and have an equal thickness.Thus, it is possible to greatly reduce deformation at the time of themolding, and also touching of the prism 12 with fingers, hands, etc. canbe prevented. Further, since the optical measurement apparatus has alarge number of vessels formed in it, it naturally has a large number ofside walls defining the individual vessels. Thus, the mechanicalstrength of the optical measurement apparatus as a whole is improved. InFIG. 20, the slight shoulder formed on the edge of the opening is forobtaining a reliable seal by the seal member.

Labeled B in FIG. 19 is a nozzle orbit. The nozzle is adapted to proceedright above the reaction vessel 24 and stirring, multi-function, labelsolution and detection vessels 52 to 55. The movement of the nozzle,which is necessary for the optical measurement, may be caused along theorbit B. The nozzle, however, has to be moved to be right above thediluting solution vessel 51. This movement may be caused in aconsiderably early stage in the optical measurement. Thus, to this endthe nozzle is moved along an orbit other than the orbit B.

For carrying out normal fluorescent immunity measurement with theoptical measurement apparatus of the above construction, a solutioncontaining fluorescent label antibodies is preliminarily accommodated inthe label solution vessel 54.

First, the seal member (not shown) is separated, and then the liquidunder test, for instance blood, is poured into the detection vessel 55by tilting a test tube containing the liquid with the edge of opening ofthe test tube engaged in the notch 55a. Then, the optical measurementapparatus is positioned by engaging the engagement recesses 56a and 56bwith the chuck pawls (not shown). Subsequently, the nozzle (not shown)is moved to be right above the stirring and detection vessels 52 and 55and then lowered for withdrawal of necessary quantities of the dilutingsolution and liquid under test. Then, the nozzle is raised and moved tobe right above the stirring vessel 53, and then it is lowered fordischarge of the diluting solution and liquid under test. In this state,the withdrawal and discharge are made by the nozzle repeatedly by anecessary number of times, thus attaining the stirring of the dilutingsolution and liquid under test.

After the above pre-treatment has been completed, the nozzle is causedto withdraw the diluted liquid under test n the stirring vessel 53, thenraised, then moved to be right above the reaction vessel 53 and thenlowered for discharging the diluted liquid under test. As a result, anantigen-antibody reaction is brought about between antibodies havingbeen attached to the optical waveguide body 11 and antigens contained inthe diluted liquid under test. After the antigen-antibody reaction hasbeen carried out for a predetermined period of the, the nozzle is causedto withdraw all the liquid under test in the reaction vessel 24, thenraised and then moved to a discarding section (not shown) fordischarging the liquid under test. At this the, the nozzle is washed, ifnecessary. Afterwards, the nozzle is moved to be right above the labelsolution vessel 54, then lowered for withdrawal of the solutioncontaining fluorescent label antibodies, then raised and then moved tobe right above the reaction vessel 24. It is then lowered for dischargeof the solution containing the fluorescent label antibodies. As aresult, an antigen-antibody reaction is brought about between theantigens restrained in the neighborhood of the surface of the opticalwaveguide body 11 and the fluorescent label antibodies. With thisantigen-antibody reaction, the fluorescent label antibodies arerestrained in the neighborhood of the surface of the optical waveguidebody 11. Thus, the label fluorescent material in the restrainedfluorescent label antibodies is excited by the evanescent wave componentto radiate a peculiar fluorescent light. Of course, the excitation lightthat has been introduced into the optical waveguide body 11 through theprism 12, is ultimately led to the light absorber vessel 25, and thereis substantially no component returning toward the prism 12. Inaddition, there is substantially no influence of fluorescent light whichis liable to be radiated from the label solution vessel 54. It is thuspossible to determine the degree of the immunity reaction highlyaccurately according to the peculiar fluorescent light.

When making measurement of hepatitis label, cancer label, etc. by usingthe above optical measurement apparatus, a solution containing biotinlabel antibodies is preliminarily accommodated n the label solutionvessel 54, and a solution containing fluorescent label avidin isaccommodated in the multi-function vessel 53.

In this case, an antigen-antibody reaction is brought about between theantigens 31 contained in the liquid under test and antibodies 3 attachedin advance to the optical waveguide body 11. Then, after discarding theliquid under test, the nozzle is moved to be right above themulti-function vessel 53, then lowered for withdrawal of the solutioncontaining biotin label antibodies 73, then raised, then moved to beright above the reaction vessel 24 and then lowered for discharge of thesolution containing the biotin label antibodies 73. As a result, anantigen-antibody reaction is brought about between the antigens 31restrained in the neighborhood of the surface of the optical waveguidebody 11 and the biotin label antibodies 73. Subsequently, the solutioncontaining the biotin label antibodies 73 is withdrawn and discardedlike the liquid under test. Then, the nozzle is brought to be rightabove the label solution vessel 54, then lowered for withdrawal of thesolution containing the fluorescent label avidin 72, then raised, thenmoved to be right above the reaction vessel 24 and then lowered fordischarge of the solution containing the fluorescent label avidin 72. Asa result, biotin 73a restrained in the neighborhood of the surface ofthe optical waveguide body 11 and the fluorescent label avidin 72 arecoupled together by the antigen-antibody reaction noted above. As aresult of this coupling, the fluorescent label avidin 72 is restrainedin the neighborhood of the surface of the optical waveguide body 11. Thelabel fluorescent material 72a in the restrained fluorescent labelavidin 72 thus is excited by the evanescent wave component to radiatepeculiar fluorescent light. With the coupling of the biotin 73a andavidin 72, a sufficient amount of fluorescent light can be radiated,because the amount of label fluorescent material that is restrained inthe neighborhood of the surface of the optical guide body 11 is as muchas several times (i.e., 5 to 10 times) the amount of the labelfluorescent material restrained by the fluorescent label antibodies, asshown in FIG. 22. On the basis of this fluorescent light, the opticalmeasurement can be attained.

The above embodiments of the invention are by no means limitative. Forexample, it is possible to attach antigens or hapten, instead of theantibodies 3, to the optical waveguide body 11. Also, the prism 12 forintroducing excitation light into the optical waveguide body 11, mayhave other shapes than in the above embodiments, for instance asymmetrical wedge-like shape. Further, using fluorescent light,scattering, polarization, etc., it is possible to measure changes inoptical characteristics stemming from other coupling reactions than theantigen-antibody reaction, catalytic reactions due to enzymes, etc.Further, it is possible to form some of the plurality of side wallsdefining the plurality of vessels to have a smaller height than theother side walls. Various further changes and modifications are possiblewithout departing from the gist of the invention.

POSSIBILITY OF INDUSTRIAL UTILIZATION

Since the invention permits measurement of optical characteristics ofthe neighborhood of an optical waveguide surface depending on anantigen-antibody reaction or the like according to the evanescent wavecomponent, it is extensively applicable as optical measurementapparatuses for various medical diagnosis purposes.

What is claimed is:
 1. An apparatus for use in an optical measurementassembly, said apparatus comprising a plurality of vessels (21 to 24, 51to 55) formed together as a monolithic molding, at least one of saidvessels being a reaction vessel (24), said reaction vessel (24) facingat least one other vessel along a facing side wall of said monolithicmolding, the facing side wall of said reaction vessel also being anoptical waveguide (1) in said apparatus.
 2. The apparatus according toclaim 1, wherein antigens, antibodies or hapten are attached to at leastone side surface of said optical waveguide (1).
 3. The apparatusaccording to claim 1, wherein said optical waveguide (1) has an inclinedform such that said reaction vessel (24) has a bottom which is narrowerthan an opened top of said vessel.
 4. The apparatus according to claim1, wherein said reaction vessel is dimensioned and arranged for atreatment of a substance and wherein there are a plurality of vesselsother than said reaction vessel formed in said monolithic molding, andat least one of said plurality of other vessels is a pre-treatmentvessel (21 to 24, 51 to 54).
 5. The apparatus according to claim 4,wherein there are a plurality of pre-treatment vessels (21 to 24, 51 to54) which said plurality of pre-treatment vessels include a reagentvessel (54) and/or a diluting solution vessel (51).
 6. The apparatusaccording to claim 5, wherein one of said pre-treatment vessels is areagent vessel (54) for storing a fluorescent material and does notshare said facing side wall of said reaction vessel (24).
 7. Theapparatus according to claim 5, which further comprises a seal (6) whichcovers at least one of said reagent vessel (54) and said dilutingsolution vessel (51).
 8. The apparatus according claim 2, wherein saidoptical waveguide (1) has a light incidence/emission prism (12) providedat one end for introducing excitation light into it in order for theexcitation light to be propagated while being totally reflected and alsofor emitting signal light containing optical measurement information, alight absorber storing vessel (25) being disposed such as to correspondto the other end of said optical waveguide (1).
 9. The apparatusaccording to claim 1 wherein said optical waveguide (1) has a lightincidence/emission prism (12) provided at one end for introducingexcitation light into it in order for the excitation light to bepropagated while being totally reflected and also for emitting signallight containing optical measurement information, said optical waveguide(1) also being formed with a total reflection prism (16) provided at theother end for emitting excitation light in a direction at apredetermined angle with respect to an optical axis of said opticalwaveguide (1).
 10. The apparatus according to claim 1, wherein saidoptical waveguide (1) has a light incidence/emission prism (1) providedat an end thereof for introducing excitation light into it in order forthe excitation light to be propagated while being totally reflected andalso emitting signal light containing optical measurement information,light penetration blocking means (27) for blocking light penetration,said light penetration blocking means being provided in a predeterminedarea adjacent an excitation light introduction area of said lightincidence/emission prism (12).
 11. The apparatus according to claim 2,wherein a side portion of said reaction vessel (24) that extendssubstantially at right angles to said optical waveguide (1), and that ispositioned on an excitation light introduction side of said opticalwaveguide (1) and/or on a side extending substantially parallel to saidoptical waveguide (1) is coated with a black paint (24b, 24c).
 12. Theapparatus according to claim 1, which further comprises a light detector(5, 46) for detecting signal light emitted from said optical waveguide(1) and an analyzer (50) for analyzing immunity reactions according to adetection signal from said light detector (5, 46).
 13. The apparatusaccording to claim 1 wherein said optical waveguide (1) has a lightincidence/emission prism (1) provided at an end thereof for introducingexcitation light into it in order for the excitation light to bepropagated while being totally reflected and also emitting signal lightcontaining optical measurement information.
 14. The apparatus accordingto claim 1 wherein said facing side wall includes an upper portion and alower portion, the lower portion includes two partitioning wall sectionswhich branch off from one end of said upper portion, a first of said twopartitioning wall sections being inclined away from said upper portionand toward an opposite side wall of said reaction vessel so as to form aspace between said two partitioning wall sections.
 15. The apparatusaccording to claim 14 wherein said first partitioning wall section isthe optical waveguide and thus has flat, opposite surfaces fortransmitting light in a totally reflected manner.
 16. An apparatus foruse in an optical measurement assembly, said apparatus comprising aplurality of vessels formed together as a monolithic unit, at least oneof said vessels being a reaction vessel, said reaction vessel facing atleast one other vessel along a facing side wall of said monolithic unit,the facing side wall of said reaction vessel being an optical waveguidein said apparatus for optical measurement wherein said optical waveguidehas a light incidence/emission prism provided at one end for introducingexcitation light into it in order for the excitation light to bepropagated while being totally reflected and also for emitting signallight containing optical measurement information, and a light absorberstoring vessel being disposed such as to correspond to the other end ofsaid optical waveguide.
 17. An apparatus for use in an opticalmeasurement assembly, said apparatus comprising a plurality of vesselsformed together as a monolithic molding, at least one of said vesselsbeing a reaction vessel, said reaction vessel facing at least one othervessel along a facing side wall of said monolithic molding, the facingside wall of said reaction vessel being an optical waveguide in saidapparatus for optical measurement, wherein a side portion of saidreaction vessel that extends substantially at right angles to saidoptical waveguide and that is positioned on an excitation lightintroduction side of said optical waveguide and/or on a side extendingsubstantially parallel to said optical waveguide is coated with a blackpaint.
 18. An apparatus according to claim 1 wherein said facing sidewall has flat, opposite surfaces for transmitting light in a totallyreflected manner.